In order to obtain good taste quality in food being cooked, it is necessary to season such food with accurately measured quantitites of salt or other seasonings. In the prior art, the adding of additional salt to foods being cooked in steam-operated cookers, for one reason or another, was impossible or only incompletely possible. For example, in stewed potatoes, the natural salt contained in the potato is insufficient to produce good taste quality so that the potatoes must receive additional crystalline salt before the steaming process by mixing or enrichment. It is also known to let the potatoes stand some time in a cold saline solution before the steaming process. However, this latter process does not produce the same taste quality as potatoes cooked in salt water.